This invention relates to clutch dampers and more particularly to clutch dampers having frictional damping in parallel with the spring damping.
Most damper mechanisms have torque transmission clutches incorporating a spring damper and a friction damper. The friction damper is active in both directions of damping; that is, during transient torque increases and transient torque decreases. The frictional damping is present to absorb a portion of the transient torque. The frictional damping also causes a hysteresis or lag when the torsional transient reverses direction. When utilizing frictional damping in both directions, only the spring rate of the damper is effective. By modifying only the spring rate, the damper can still permit some noise and vibration transmission during a torque transient.